This injury is a tearing of the ACL ligament in the knee joint. The ACL ligament is one of the bands of tissue that connects the femur to the tibia. An ACL tear can be painful. It can cause the knee to become unstable.
An ACL tear usually occurs during athletic activity. The ACL can tear during abrupt movements such as sudden stops, pivots or directional changes. The ACL can also tear when a person jumps and lands awkwardly. In some cases, ACL tears are caused by a traumatic injury such as a vehicular accident or a violent tackle.
A common symptom of an ACL tear is a popping sound or sensation in the knee at the moment of injury. The knee may be very painful, and it may swell. It may feel unstable. The person may be unable to continue physical activity.
In some cases, an ACL tear can be treated conservatively in patients who have a low activity level. Nonsurgical options may include crutches, a knee brace, and strengthening and stability exercises. For active patients, surgery and rehabilitation are commonly required.